Barack Obama is not the first President of the United States to confess to
experimenting with recreational drug-use in those heady days before the
gruelling demands of Washington took over.

However, while Bill Clinton notoriously "didn't inhale" at Oxford, Mr Obama took an altogether more enthusiastic approach to smoking marijuana in his youth, according to a new biography.

As a secondary school pupil in Honolulu, Hawaii, in the late 1970s, Mr Obama is said to have been a member of the "Choom Gang", a group of boys who played basketball and choomed, or smoked dope.

"Barry Obama was known for starting a few pot-smoking trends," according to David Maraniss, a Pulitzer Prize-winning author. "The first was called 'TA,' short for 'total absorption'." Mr Obama's favoured technique is described as "the antithesis" to Mr Clinton's eyebrow-raising claim to have barely participated in – and certainly not enjoyed – smoking the drug as a Rhodes scholar at University College from 1968 to 1970.

Any Choom Gang members caught daring to exhale before absorption was total "were assessed a penalty" and faced being "skipped the next time the joint came around," according to 'Barack Obama: The Story'.

All told, the future president is said to have been a bit of a drag. "When a joint was making the rounds, he often elbowed his way in, out of turn, shouted 'Intercepted!,' and took an extra hit," said Maraniss.

He also reportedly popularised "roof hits" after smoking in cars with the windows closed: "When the pot was gone, they tilted their heads back and sucked in the last bit of smoke from the ceiling." Former members recalled to Maraniss that the gang's favoured vehicle was a "Volkswagen bus, also known as the Choomwagon", that belonged to fellow member Mark Bendix.

The disclosures are unlikely to harm Mr Obama politically. In addition to a relaxation in attitudes towards soft drugs since Mr Clinton's confession 20 years ago, voters knew when they elected him in 2008 that Mr Obama had also tried cocaine while a university student in New York.

Recalling personal struggles from that time in his 1995 memoir, 'Dreams From My Father', Mr Obama wrote: "Pot had helped, and booze; maybe a little blow when you could afford it". He added that he had never tried heroin.

A Rasmussen poll earlier this month claimed that 56 per cent of Americans favoured legalising and regulating marijuana like alcohol and tobacco, while 36 per cent remained opposed.

None the less, the future president appears to have been remarkably indiscreet about his activities. In his high school yearbook entry he thanked the "Choom Gang, and Ray for all the good times".

Maraniss writes that Ray, a long-haired hippie who worked in a pizza parlour, was the group's drug-dealer. "Many years later they learned that he had been killed with a ball-peen hammer by a scorned gay lover," according to the book.

The excerpts were published by BuzzFeed, a website. They emerged after Mitt Romney, Mr Obama's presumed Republican opponent, faced embarrassment over disclosures about his own school days.

Mr Romney was alleged to have led a boisterous gang during his final year at Cranbrook School, Michigan, in 1965. He and the group, which was likened by an onlooker to something from 'Lord of the Flies', are alleged to have pinned down a pupil who was presumed to be homosexual and forcibly chopped off his fringe with scissors.

Both findings appeared to match the caricatures of each man drawn by their opponents decades later: Mr Obama as an unabashed liberal and Mr Romney as a ruthless bully.